We consider the general properties of central charges of 0-branes and associated duality invariants, in view of their double role, on the bulk and on the world volume (quantum mechanical) theory. A detailed study of the BPS condition for the mass spectrum arising from toroidal compactifications is given for 1/2, 1/4, and 1/8 BPS states in any dimension. As a by-product, we retrieve the U-duality invariant conditions on the charge (zero mode) spectrum and the orbit classification of BPS states preserving different fractions of supersymmetry. The BPS condition for 0-branes in theories with 16 supersymmetries in any dimension is also discussed.

• Received 16 March 1999

DOI:https://doi.org/10.1103/PhysRevD.60.084007